I wanted to make an animation for simple harmonic motion. I used the sin function. It worked great.
I then wanted to make an animation showing a ball bouncing in a box. The sin wave motion did not look correct. I needed a saw tooth wave. No saw tooth function exists.
I did a simple Fourier analysis. I found an approximated sawtooth wave could be had by.
wave sawtooth = .95 sin t - .5 sin 3t
It looks better.
here is the link that shows the two motions. Can you see the difference?
Chapter 7
here is the script that gets embedded into the HTML
<SCRIPT language="JScript">
count2=0;
function onInterval2() {
with(document.body)
{
if(clientWidth>200)
{
{imagefly2.style.left= 81*( .95*Math.sin(count2) - .05*Math.sin(3*count2))+ (clientWidth -305);}
imagefly2.style.top=158;
count2=count2+.07;
if(count2>4300)
{count2 = 0;}
}
}
}
writeRetrun("");
setInterval("imagefly2.style.display='';onInterval2();",30);
function writeRetrun(displaySetting) {
var frmSnip=' style="POSITION:Relative;background-color:none;top:0;left:'+0;
document.writeln('<DIV align=left id=imagefly2'+frmSnip+'display:none;visibility:visible;"><IMG SRC="" border=0 USEMAP="" name=sticky_map><area coords=95,0,130,158 href="" ></map></DIV>');
}
</SCRIPT>
enjoy
Frank Znidarsic
